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Alkalic to tholeiitic magmatism near a mid-ocean ridge: petrogenesis of the KR1 Seamount Trail adjacent to the Australian-Antarctic Ridge

Cited 2 time in wos
Cited 2 time in scopus
Title
Alkalic to tholeiitic magmatism near a mid-ocean ridge: petrogenesis of the KR1 Seamount Trail adjacent to the Australian-Antarctic Ridge
Other Titles
중앙해령 주변부에서의 알칼리-쏠레아이트 화성작용: 호주-남극해령 권역 KR1해산열의 형성 과정
Authors
Yi, Sang-Bong
Lee, Mi Jung
Park, Sung Hyun
Nagao, Keisuke
Han, Seunghee
Yang, Yun Seok
Choi, Hakkyum
Baek, Jongmin
Sumino, Hirochika
Subject
Geology
Keywords
KR1 Seamount TrailPREMA (FOZO)alkaline basaltrecycled oceanic crusttholeiite
Issue Date
2021-06-03
Citation
Yi, Sang-Bong, et al. 2021. "Alkalic to tholeiitic magmatism near a mid-ocean ridge: petrogenesis of the KR1 Seamount Trail adjacent to the Australian-Antarctic Ridge". INTERNATIONAL GEOLOGY REVIEW, 63(10): 1215-1235.
Abstract
Coexisting alkalic and tholeiitic basalt lavas has been identified in a seamount chain located near the Australian-Antarctic spreading ridge. The KR1 Seamount Trail (KR1 ST) is a series of volcanic seamounts extending to the southeast in the spreading direction of the Australian-Antarctic Ridge (AAR). We herein report Sr, Nd and Pb isotopic compositions and (U-Th)/He and K-Ar geochronology for dredge samples from the KR1 ST in order to evaluate mantle processes and the role of enriched components for alkalic to tholeiitic magma generation in this region. The KR1 ST is a medium-sized seamount chain that extends for ~60 km, has a maximum height of ~1600 m above the seafloor, and consists of alkaline basalts and tholeiites with formation ages of ~0.4 Ma to ≤1.3 Ma. The isotopic characteristics of the alkaline basalts (206Pb/204Pb = 19.52-19.91; 87Sr/86Sr = 0.7030-0.7033; 143Nd/144Nd = 0.5128-0.5130) from the KR1 ST reflect a dominant ‘PREMA (or FOZO)’ mantle component represented by radiogenic Pb and mildly enriched Sr and Nd isotopic compositions. On the other hand, the weak PREMA (FOZO)-affinity (206Pb/204Pb = 18.89-18.93; 87Sr/86Sr = 0.7028-0.7029; 143Nd/144Nd = ~0.5130; 3He/4He = 7.64 ± 0.13 (R/RA)) coupled with their enriched mid-ocean ridge basalt (E-MORB) characteristics of tholeiites from the KR1 ST largely overlap with the KR1 MORB composition. The potential source materials for the alkaline basalts are considered to be ancient, recycled oceanic crust (i.e. eclogite) as well as sub-KR1 depleted MORB mantle (DMM). Whereas the main source materials for the KR1 ST tholeiites are presumed to be the DMM-dominant lithology with minor recycled material. We interpret the KR1 ST as a submarine hotspot chain that was formed by asthenospheric upwelling and spreading processes that delivered fertile blobs of recycled oceanic crust to the sub-KR1 region. The fundamental reason for sub-KR1 upper mantle enrichment might be attributed to a mantle plume event that possibly occurred prior to the formation of the KR1 ST.
URI
https://repository.kopri.re.kr/handle/201206/12984
DOI
http://dx.doi.org/10.1080/00206814.2020.1756002
Type
Article
Station
Araon
Indexed
SCIE
Appears in Collections  
2020-2020, Antarctic geology and meteorite research based on the Jangbogo station: Crustal evolution of Victoria Land and characteristics of asteroidal materials (20-20) / Lee, Mi Jung (PE20200)
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